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Abstract:

An exhaust gas treatment unit includes a substantially cylindrical
exhaust gas treatment body having a main axis and, on at least one
opening side of the exhaust gas treatment unit, at least one of the
following connecting devices or connectors: an offset compression zone or
a molded structure for form-locking engagement. An internal combustion
engine includes at least one exhaust gas treatment unit and at least one
exhaust gas conducting line. The at least one exhaust gas treatment unit
is completely introduced in the at least one exhaust gas conducting line.
A motor vehicle having at least one exhaust-gas treatment unit is also
provided.

Claims:

1. An exhaust-gas treatment unit, comprising: at least one opening side;
a substantially cylindrical exhaust-gas treatment body having a main
axis; and at least one connector disposed on said at least one opening
side, said at least one connector being an offset crimp zone or a shaped
structure configured for form-locking engagement.

2. The exhaust-gas treatment unit according to claim 1, wherein said at
least one connector has a cross section differing from said substantially
cylindrical exhaust-gas treatment body.

3. The exhaust-gas treatment unit according to claim 1, wherein said at
least one connector is disposed eccentrically relative to said main axis.

4. The exhaust-gas treatment unit according to claim 1, which further
comprises a housing formed in one piece with said at least one connector.

5. An internal combustion engine, comprising: at least one
exhaust-gas-conducting line; and at least one exhaust-gas treatment unit
inserted entirely into said at least one exhaust-gas-conducting line.

6. The internal combustion engine according to claim 5, wherein said at
least one exhaust-gas treatment unit is configured to be positioned
fixedly to said exhaust-gas-conducting line in a force-locking manner.

7. The internal combustion engine according to claim 5, wherein said
exhaust-gas treatment unit is fixed at least at one side by calking.

8. The internal combustion engine according to claim 5, wherein said
exhaust-gas treatment unit is the exhaust-gas treatment unit of claim 1.

9. A motor vehicle, comprising: an internal combustion engine according
to claim 5 having at least one exhaust-gas treatment unit.

Description:

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is a continuation, under 35 U.S.C. §120, of
copending International Application No. PCT/EP2011/066160, filed Sep. 17,
2011, which designated the United States; this application also claims
the priority, under 35 U.S.C. §119, of German Patent Application DE
10 2010 045 871.6, filed Sep. 17, 2010; the prior applications are
herewith incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

[0002] The present invention relates to an exhaust-gas treatment unit for
an internal combustion engine, in particular a catalyst carrier body
integrated into an exhaust-gas recirculation line (EGR line) of a motor
vehicle engine. The invention also relates to an internal combustion
engine and a motor vehicle having an integrated exhaust-gas treatment
unit.

[0003] It is known for the exhaust gases of a mobile internal combustion
engine to be purified of undesired constituents which pose a health
concern and/or are harmful to the environment, in particular in such a
way that the exhaust gases also meet the emissions requirements of future
legal regulations. Retrofit systems for the treatment of the exhaust
gases are desirable, inter alia, for that purpose, so that an adaptation
of existing engine concepts to future exhaust-gas purification targets is
made possible in a simple manner. Likewise, constant efforts are being
made to integrate the exhaust-gas treatment units required for that
purpose in the vehicle in a particularly effective, space-saving and
inexpensive manner.

[0004] One possibility for meeting those requirements is, for example, the
provision of a so-called close-coupled catalytic converter which is
positioned in the direct vicinity of the internal combustion engine and,
if appropriate, even partially in an engine outlet and/or a manifold
inlet. An example of such a catalyst carrier body for close-coupled
installation is disclosed in European Patent EP10 09 924 B1,
corresponding to U.S. Pat. No. 6,660,235.

[0005] Such exhaust-gas treatment units are generally inserted into the
exhaust-gas-conducting lines and are fixedly connected by a fastening
device or fastener situated at the outside such as, for example, a flange
and/or a collar, to the internal combustion engine and/or the exhaust
line (the manifold), and positioned by using structural elements (for
example screw connections) and/or weld seams. The production of such a
flange/collar is cumbersome, however, so that in that case, considerable
costs are incurred specifically with regard to mass production.

SUMMARY OF THE INVENTION

[0006] It is accordingly an object of the invention to provide an exhaust
gas treatment unit for an exhaust gas recirculation line and an internal
combustion engine and a motor vehicle having an exhaust-gas treatment
unit, which overcome the hereinafore-mentioned disadvantages and at least
partially solve the highlighted problems of the heretofore-known units,
engines and vehicles of this general type. In particular, it is sought to
permit a space-saving and secure integration of an exhaust-gas treatment
unit in the vicinity of the internal combustion engine. It is furthermore
also sought to achieve an inexpensively produced and easily assembled
exhaust-gas treatment unit.

[0007] With the foregoing and other objects in view there is provided, in
accordance with the invention, an exhaust-gas treatment unit, comprising
a substantially cylindrical exhaust-gas treatment body with a main axis
and, on at least one opening side of the exhaust-gas treatment unit, at
least one of the following connecting devices or connectors:

[0008] an
offset crimp, compression, pinch or squeeze zone, and

[0009] a shaped
structure for form-locking engagement.

[0010] A form-locking connection is one which connects two elements
together due to the shape of the elements themselves, as opposed to a
force-locking connection, which locks the elements together by force
external to the elements.

[0011] The exhaust-gas treatment unit substantially constitutes a
structural unit, in the form of an auxiliary system and/or retrofit
system, through which the following functions can be realized: treatment
of the exhaust gas and permanent, fixed positioning in an
exhaust-gas-conducting line. In this case, the function of the
positioning is performed, in particular, by a (preferably one-piece)
housing. The housing forms, for example, a type of (metallic) shell
region which receives, and thus also provides dimensional stability to,
(at least) one exhaust-gas treatment body through which the exhaust gas
can flow. For this purpose, it is possible in particular for a brazed
connection and/or welded connection to the exhaust-gas treatment body to
be formed. In particular, a direct or immediate connection of the housing
and exhaust-gas treatment body is thus realized (without, for example, an
intermediate housing, mounting mats or the like).

[0012] The exhaust-gas treatment body is, in particular, a catalytically
active body. The exhaust-gas treatment body may, in particular, be
constructed from coiled and/or wound metallic sheet-metal foils, which
may be smooth and/or structured. In this case, the sheet-metal foils are
preferably disposed in such a way that a honeycomb body with a plurality
of channels or ducts (running substantially parallel to one another) is
formed. Furthermore, the foils have a catalytically active coating. In
particular, the foils include so-called washcoat and catalytically active
material applied thereto. It is preferable for the sheet-metal foils to
be in direct contact with the housing and/or connected thereto.

[0013] The exhaust-gas treatment body and the housing surrounding it
preferably have a substantially cylindrical form. This means, in
particular, that the cross-sectional shape normal to the main axis of the
exhaust-gas treatment body is substantially cylindrical.
Exhaust-gas-conducting lines are in many cases cylindrical. The basic
shape of the exhaust-gas treatment body may self-evidently also be
adapted to other cross sections of the exhaust-gas-conducting line. The
expression "substantially" thus also encompasses conventional cross
sections of the exhaust-gas-conducting lines such as, for example, an
oval, a polygon or the like. What is important in this case is the
predominantly uniform spacing to the wall of the respective
exhaust-gas-conducting line.

[0014] The main axis of the exhaust-gas treatment body is generally
congruent with the main axis of a respective exhaust-gas-conducting line.
This does not mean that the main axis must imperatively be congruent with
the direction of the filter ducts or channels of the exhaust-gas
treatment body. This rather means that the entry direction of the exhaust
gas and also the exit direction of the exhaust gas are identically
substantially normal to the main axis. The main axis is often congruent
with the normal to the geometric center of the inlet and/or outlet
surface of the exhaust-gas treatment body.

[0015] The crimp zone of the exhaust-gas treatment unit performs the task
of providing the force-locking connection to an exhaust-gas-conducting
line. The crimp zone is preferably formed (only) with the housing, in
such a way that the axial portion of the housing is in particular not
filled, or is at least not completely filled, by the exhaust-gas
treatment body. The crimp zone has, in particular, an oversize in
relation to the rest of the exhaust-gas treatment unit. The oversize is
suitable for forming force-locking contact, or an interference fit, with
the exhaust-gas-conducting line. The crimp zone is, in particular,
constructed in such a way that it deforms (radially) inward (if
appropriate also in the direction of the exhaust-gas treatment body),
preferably without (significantly) deforming the exhaust-gas treatment
body itself. In order to form the interference fit, the crimp zone may
undergo both elastic and also plastic deformation. In this case, the
plastic deformation is particularly preferable. With the plastic
deformation, it is ensured that the friction force resulting from the
elastic deformation component associated with the plastic deformation is
at a maximum. The crimp zone may, however, also be constructed in such a
way that a defective exhaust-gas treatment unit and/or a functional
exhaust-gas treatment unit installed in a damaged structural element can
be removed again with little effort and without damage to the surrounding
structural elements and/or to the exhaust-gas treatment unit.

[0016] The crimp zone may be provided in a variety of embodiments. In
particular, the crimp zone may take the form of a slotted spring ring, a
closed temperature expansion ring and/or an elongation of the housing
with a cross section which differs from the basic shape. The crimp zone
may also take the form of at least one bulge of the (in particular one
piece) housing. The bulge may be formed in such a way that a deformation
of the bulge resulting from the installation causes little to no
deformation of the rest of the housing. That is to say, in particular,
that that part of the housing which is (radially and/or axially
adjacently) in contact with the exhaust-gas treatment body is subjected
to only little to no deformation. Such a bulge may, in particular, be
formed with a spacing of up to 20 mm [millimeters], wherein it is
preferable for at least 2 and very particularly preferably at most 5
bulges to be disposed on a periphery or circumference of the housing.

[0017] The crimp zone is offset with respect to the exhaust-gas treatment
body. In this case, "offset" means in particular that no deformation
influence or only a minor deformation influence can be exerted on the
exhaust-gas treatment body, and accordingly practically only in one
portion of the housing. This may be achieved, in particular, by virtue of
an offset, a change in cross section, a change in shape of the cross
section and/or the like being provided between the crimp zone and the
exhaust-gas treatment body. Such an offset may take the form of a step, a
bend, a curve (as viewed in a longitudinal section through the housing)
and/or a cohesive connection, that is to say a welded connection and/or a
brazed connection.

[0018] The shaped structure for form-locking engagement may, in
particular, constitute a toothing which engages into a corresponding
structure in the exhaust-gas-conducting line and prevents an inadvertent
loosening during operation. The shaped structure (and a corresponding
line structure) may be constructed in such a way that the exhaust-gas
treatment unit can be removed without damage to the exhaust-gas treatment
unit and/or to the exhaust-gas-conducting line, for example in the event
of necessary repairs in the region of the exhaust-gas treatment unit. The
shaped structure may, in particular, also be a thread, and the line
structure may have a matching counterpart thread, or a thread may be
formed directly into the line during assembly. The shaped structure may,
however, very particularly preferably also constitute a toothing which,
through elastic deformation of the shaped structure or of the respective
portion of the housing, can be inserted into the corresponding structure
of the exhaust-gas-conducting line. In this case, the shaped structure is
considerably greater than the conventional roughnesses in the case of a
housing of that type, and in particular protrudes at least 1 mm
[millimeter] and particularly preferably at most 5 mm [millimeters]
beyond the outer surface of the housing.

[0019] The at least one connecting device or connector is furthermore
situated on at least one opening side of the exhaust-gas treatment unit.
This means, in particular, that portion of the housing which adjoins an
opening side. It is preferable for only a (single) crimp zone or shaped
structure to be provided, which furthermore extends, in particular, only
over a limited portion of the exhaust-gas treatment unit proceeding from
the opening side. Through the use of the connecting device or connector,
it is thus possible in particular in an assembly direction and/or
disassembly direction, for an upstream and/or downstream, force-locking
and/or form-locking connection to the exhaust-gas-conducting line to be
formed.

[0020] Even though it is possible for both connecting devices or
connectors (crimp zone and shaped structure) to be provided on a housing,
a separate provision is preferable, depending on the usage situation in a
housing, in order to keep the manufacturing outlay for the production
process low.

[0021] In accordance with another advantageous feature of the exhaust-gas
treatment unit of the invention, the at least one connecting device or
connector has a cross section which differs from the substantially
cylindrical exhaust-gas treatment body. The cross section may, in
particular, be formed so as to effect a suitable deformation with the
result of a force-locking and/or form-locking connection to an
exhaust-gas-conducting line. In this case, the cross section may
occasionally differ from the shape of the cylindrical exhaust-gas
treatment body only in places (locally), in order to thereby further
minimize the influence of the mechanical deformation on the exhaust-gas
treatment body. The cross section may also differ from the shape of the
exhaust-gas treatment body in such a way as to assist simple assembly. In
this case, consideration should be given, in particular, to cross
sections which permit the use of tools which assist an insertion with
simultaneous prestressing of the crimp zone, for example. Furthermore,
the cross section may have folds and similarly acting spring devices or
springs over the circumference, which in assist an elastic action of the
crimp zone, for example.

[0022] It is basically stated herein that the cross sections of the
exhaust-gas treatment unit in the region of the exhaust-gas treatment
body and in the region of the at least one connecting device or connector
may differ (with regard to the circumference and/or the area and/or the
overlap) by at least 2%, in particular by at least 5%. This means, in
particular, that the cross section in the region of the at least one
connecting device or connector has a non-circular and/or eccentric form
in relation to the cross section in the region of the exhaust-gas
treatment body. In this case, consideration is given in particular to
combinations of radially (at least partially) protruding cross sections
(circular shape, oval, polygon, racetrack shape, etc.).

[0023] In accordance with a further advantageous feature of the
exhaust-gas treatment unit of the invention, the at least one connecting
device or connector is disposed eccentrically with respect to the main
axis. In this way, it can in particular be achieved that the exhaust-gas
treatment unit bears partially without play against the
exhaust-gas-conducting line. This greatly assists stability. It can also
be achieved in this way that the surface which has a force-locking and/or
form-locking action extends further over the portion of the exhaust-gas
treatment unit. It is furthermore also possible in this way for there to
be provided over the circumference of the exhaust-gas treatment unit
regions which, for possible disassembly, permit an engagement of
corresponding tools.

[0024] In accordance with an added advantageous feature of the exhaust-gas
treatment unit of the invention, the exhaust-gas treatment unit has a
housing, and the housing and the at least one connecting device or
connector are formed in one piece. In this way, it is possible to avoid
disadvantages in conjunction with joining connections, reworking
operations and fluctuations in material characteristics between the at
least one connecting device or connector and the exhaust-gas treatment
unit (or the housing). It is furthermore advantageous that, in this way,
no additional structural element is required. Merely an elongation of the
housing, and/or under some circumstances further working of the housing
by deformation in the region of the desired connecting device or
connector, is then necessary.

[0025] In a further advantageous embodiment of the exhaust-gas treatment
unit according to the invention, the exhaust-gas treatment unit merges in
a flowing manner into the at least one connecting device or connector.
This means, in particular, that the housing forms a continuous slope (for
example a widening) over the entire extent of the exhaust-gas treatment
unit including the at least one connecting device or connector. In this
case, the housing may (in part) have the shape of a cone and/or of a
single-sided cone, and/or may have a bulged form and/or outwardly curved
form. This may be advantageous in particular if, in this way, the
insertion of the exhaust-gas treatment unit with a crimp zone and/or
shaped structure is assisted by the flowing transition to the crimp zone
and/or shaped structure. In order to prevent deformation of the
internally disposed exhaust-gas treatment body, both deformation portions
as well as relief slots may be provided. It is advantageous, in
particular, for the exhaust-gas treatment body to have no connection to
those parts of the shell surface (or of the housing) which merge in a
flowing manner into the crimp zone or shaped structure. This means, in
particular, that those regions of the housing of the exhaust-gas
treatment unit which are connected to the exhaust-gas treatment body have
substantially no change in cross section over the entire extent of the
exhaust-gas treatment unit.

[0026] With the objects of the invention in view, there is also provided
an internal combustion engine, comprising at least one exhaust-gas
treatment unit, and at least one exhaust-gas-conducting line, wherein the
at least one exhaust-gas treatment unit is inserted entirely in the at
least one exhaust-gas-conducting line.

[0027] The internal combustion engine is constructed as a conventional
internal combustion engine and is constructed for operation with gasoline
or diesel fuel. The internal combustion engine may thus be a conventional
reciprocating-piston engine or plunger-piston engine (for example
Otto-cycle engine or diesel engine), a rotary piston engine or a rotary
engine (Wankel engine). Operation with other internal combustion engines
based on a closed cycle is also conceivable. In this case, the internal
combustion engine is preferably part of a motor vehicle, in particular of
an automobile.

[0028] Exhaust-gas-conducting bores are provided for the expulsion of the
burned mixture from the internal combustion engine. Furthermore, internal
combustion engines are known in which, according to demand, a part of the
(untreated) exhaust gas is recirculated again (exhaust-gas recirculation
line or EGR line). The expression "exhaust-gas-conducting line" thus
encompasses not only the conventional exhaust-gas-conducting bores but
also the bores provided in the internal combustion engine for the intake
line. It is important in this case, in particular, that these are lines
(or bores, etc.) which are (at least partially and/or intermittently)
traversed by exhaust gas, which are integrated into the internal
combustion engine and which are formed and/or enclosed by the engine
casing. The lines are thus particularly stable and may constitute a
corresponding counterbearing for a crimp zone of the exhaust-gas
treatment unit. This refers, in particular, to a line portion which
extends through a part of the internal combustion engine, in particular
in the form of a bore through the cylinder head, of an
exhaust-gas-recirculating line. In particular, the respective line
portion is situated, as viewed in the flow direction of the exhaust gas,
upstream of any exhaust-gas cooling device that may be provided for the
treatment of the exhaust gases, for example for recirculation into at
least one combustion chamber of the internal combustion engine. In
particular, the exhaust-gas-conducting line is formed so as to be rigid
in relation to the housing of the exhaust-gas treatment unit as a whole
or only in relation to the crimp zones.

[0029] The exhaust-gas treatment unit is, in particular, formed in such a
way that it is received entirely by the exhaust-gas-conducting line. In
other words, this also means in particular that the exhaust-gas treatment
unit is completely surrounded by the exhaust-gas-conducting line without
interrupting or penetrating the exhaust-gas-conducting line, wherein the
exhaust-gas-conducting line has a one-piece form preferably in the entire
region around the exhaust-gas treatment unit and/or has no partition,
receptacle, widening, etc. running in the circumferential direction of
the exhaust-gas treatment unit. This also means, in particular, that no
components of the exhaust-gas treatment unit project out of the
exhaust-gas-conducting line. It is thus the case firstly that the
flexibility of the configuration of the exhaust-gas treatment unit in an
exhaust-gas-conducting line is increased, with the line no longer being
constricted in flange regions, and secondly structural modifications,
cumbersome sealing devices or seals and, in particular, additional
components of the exhaust-gas treatment unit can be dispensed with.
Overall, the number of required construction and assembly steps is
decreased.

[0030] In accordance with another advantageous feature of the internal
combustion engine of the invention, the at least one exhaust-gas
treatment unit can be positioned fixedly with the exhaust-gas-conducting
line in a force-locking manner. In this case, the exhaust-gas treatment
unit can, in particular, be positioned fixedly by an interference fit by
using an oversize in relation to the exhaust-gas-conducting line. The
oversize of the exhaust-gas treatment unit may either already be provided
at room temperature before installation, or else may first impart its
adequate force in the operating state at operating temperature.
Furthermore, the oversize may also first be realized retroactively during
installation by using an additional structural element such as a
temperature expansion ring.

[0031] In accordance with a further advantageous feature of the internal
combustion engine of the invention, the exhaust-gas treatment unit is
fixed at least at one side by calking. In this case, the line wall of the
exhaust-gas-conducting line is deformed at one opening side in such a way
that force-locking and form-locking are generated between the exhaust-gas
treatment unit and the exhaust-gas-conducting line. The fixing device or
fixation is suitable, in particular, for aluminum lines, for example
lines formed as a bore into an aluminum cylinder head. Further fixing may
also be produced in this way, in particular in the case of conical bores,
for example.

[0032] In accordance with an added advantageous feature of the internal
combustion engine of the invention, at least one of the exhaust-gas
treatment units provided herein corresponds to the above-described
exhaust-gas treatment unit according to the invention having at least one
connecting device or connector.

[0033] With the objects of the invention in view, there is concomitantly
provided a motor vehicle, comprising an internal combustion engine
according to the invention with at least one exhaust-gas treatment unit
according to the invention.

[0034] Other features which are considered as characteristic for the
invention are set forth in the appended claims, noting that the features
specified individually in the claims may be combined with one another in
any desired technologically expedient manner and form further embodiments
of the invention.

[0035] Although the invention is illustrated and described herein as
embodied in an exhaust gas treatment unit for an exhaust gas
recirculation line and an internal combustion engine and a motor vehicle
having an exhaust-gas treatment unit, it is nevertheless not intended to
be limited to the details shown, since various modifications and
structural changes may be made therein without departing from the spirit
of the invention and within the scope and range of equivalents of the
claims.

[0036] The construction and method of operation of the invention, however,
together with additional objects and advantages thereof will be best
understood from the following description of specific embodiments when
read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0037]FIG. 1 is a diagrammatic, side-elevational view of an exhaust-gas
treatment unit with a crimp zone;

[0038]FIG. 2 is a cross-sectional view of the exhaust-gas treatment unit
of FIG. 1;

[0039]FIG. 3 is a side-elevational view of a further exhaust-gas
treatment unit with an eccentric crimp zone and a deviating cross
section;

[0040]FIG. 4 is a cross-sectional view of the exhaust-gas treatment unit
of FIG. 3;

[0041]FIG. 5 is a side-elevational view of an exhaust-gas treatment unit
with a flowing transition from an exhaust-gas treatment body to the crimp
zone;

[0042]FIG. 6 is a cross-sectional view of the exhaust-gas treatment unit
of FIG. 5;

[0043]FIG. 7 is a side-elevational view of an exhaust-gas treatment unit
with bulges at two opening sides;

[0044]FIG. 8 is a cross-sectional view of an exhaust-gas treatment device
with a bulged connecting device;

[0045]FIG. 9 is a cross-sectional view of an exhaust-gas treatment unit
in an exhaust-gas-conducting line with calking;

[0046] FIG. 10 is a partly longitudinal-sectional view of an exhaust-gas
treatment unit in an exhaust-gas-conducting line with a shaped structure;

[0047] FIG. 11 is a plan view of a portion of a motor vehicle having four
exhaust-gas treatment units in an intake line;

[0048] FIG. 12 is a partly longitudinal-sectional view of an exhaust-gas
treatment unit in an intake line;

[0049] FIG. 13 is a plan view of a portion of a motor vehicle having four
exhaust-gas treatment units in the exhaust line; and

[0050] FIG. 14 is a partly longitudinal-sectional view of an exhaust-gas
treatment unit in an exhaust line.

DETAILED DESCRIPTION OF THE INVENTION

[0051] Referring now to the figures of the drawings in detail and first,
particularly, to FIG. 1 thereof, there is seen an exhaust-gas treatment
unit 1 having a housing 15, a (single) exhaust-gas treatment body 3, a
crimp, compression, pinch or squeeze zone 5 at one opening side 2 and a
main axis 4. The crimp zone 5 is concentric with the main axis of the
exhaust-gas treatment body 3 and also has a step relative to the
exhaust-gas treatment body 3. FIG. 2 shows a plan view of the opening
side 2 of the exhaust-gas treatment unit 1 and a cross section 6 of the
crimp zone 5 relative to the exhaust-gas treatment body 3 of FIG. 1. It
can be seen therein that the cross section 6 corresponds to the shape of
the exhaust-gas treatment body 3. A structure composed of alternating
corrugated and smooth foils wound in an S-shape is illustrated therein
representatively for various honeycomb structures.

[0052]FIG. 3 shows an exhaust-gas treatment unit 1 having an exhaust-gas
treatment body 3 and a crimp zone 5 which is situated on an opening side
2 of the exhaust-gas treatment unit 1. It can be seen even in this view
that the crimp zone 5 is disposed eccentrically.

[0053]FIG. 4 is a plan view showing the opening side 2 of the exhaust-gas
treatment unit 1 of FIG. 3 and illustrating that the cross section 6 is
disposed eccentrically with respect to the main axis 4. It can also be
seen that the cross section 6 deviates from the shape of the exhaust-gas
treatment body 3.

[0054]FIG. 5 shows an exhaust-gas treatment unit 1 having an exhaust-gas
treatment body 3 and a crimp zone 5 at the opening side 2, in which a
transition from the exhaust-gas treatment body 3 to the crimp zone has a
flowing or free-flowing form. Merely for clarification, a thin dashed
line is shown which divides the exhaust-gas treatment body 3 from the
crimp zone 5. The main axis 4 is illustrated in FIG. 5 as being inclined,
although it may also, in the case of a deviating form of the internal
configuration of the exhaust-gas treatment body 3, be plotted
horizontally in relation to the illustration.

[0055]FIG. 6 is another plan view showing the opening side 2 and the
cross section 6 of the exhaust-gas treatment unit 1 of FIG. 5. It can be
seen therein that the cross section 6 deviates only partially from the
shape of the exhaust-gas treatment body 3.

[0056]FIG. 7 shows an exhaust-gas treatment unit 1 having an exhaust-gas
treatment body 3 and two crimp zones 5 at two respective opening sides 2,
in which a transition from the exhaust-gas treatment body 3 to the crimp
zone has a flowing or free-flowing form. Merely for clarification, oval
lines are shown which indicate the elevation of the crimp zone 5 in
relation to the exhaust-gas treatment body 3. In each case three bulges
are formed into both crimp zones over the circumference of the
exhaust-gas treatment unit 1.

[0057]FIG. 8 shows, by way of example, a section taken along a line
VIII-VIII in FIG. 7, in the direction of the arrows, which is superposed
on a planned installation situation in an exhaust-gas-conducting line 7.
It can be seen therein that the cross section 6 deviates (inwardly and
outwardly) from the shape of the exhaust-gas-conducting line 7 over the
entire circumference of the exhaust-gas treatment unit 1. If the
exhaust-gas treatment unit 1 is actually inserted, the housing 15 deforms
in the region of the crimp zones 5, although the exhaust-gas treatment
body 3 is not significantly affected thereby.

[0058]FIG. 9 is a plan view of an opening side 2 showing the cross
section 6 of an exhaust-gas treatment unit 1 pushed into an
exhaust-gas-conducting line 7 in an internal combustion engine 11. Two
calking points 17, which prevent the exhaust-gas treatment unit 1 from
becoming detached, are illustrated therein by way of example.

[0059] FIG. 10 is a partly-sectional, side view showing an exhaust-gas
treatment unit 1 pushed into an exhaust-gas-conducting line 7 in an
internal combustion engine 11. In this case, the exhaust-gas treatment
unit 1 has an offset connecting device or connector with a shaped
structure 16. The shaped structure 16 is latched in a form-locking manner
into a corresponding line structure 18. The housing 15 bears, over the
entire circumference, against the exhaust-gas-conducting line 7, but in
the region of the shaped structure 16 has a notch formation in order to
ensure that the exhaust-gas treatment unit 1 can be inserted over the
line structure 18 from right to left as seen in the illustration in the
figure.

[0060] FIG. 11 shows a motor vehicle 10 having an internal combustion
engine 11. The internal combustion engine 11 has an exhaust line 12 which
leads from a combustion chamber 14 to the outside. Furthermore, the
internal combustion engine 11 also includes an air line 13 which supplies
air from the outside to the combustion chamber. The air line is
supplemented by an exhaust-gas-conducting line 7 through which exhaust
gases coming from the exhaust line 12 and passing through an exhaust-gas
recirculation line 9 are recirculated, in a mixture with air from the air
line 13, into the combustion chamber 14. Before the exhaust-gas/air
mixture can enter the combustion chamber 14, it is purified by the
exhaust-gas treatment units 1 situated upstream.

[0061] FIG. 12 shows, in detail, a configuration of the exhaust-gas
treatment unit 1 in the internal combustion engine 11 or the
exhaust-gas-conducting line 7. As a result of the spacing between the
exhaust-gas treatment unit 1 and the exhaust-gas-conducting line 7, it
can be seen that it is possible for only the crimp zone 5, but not the
exhaust-gas treatment body 3, to be in contact with the
exhaust-gas-conducting line, although this is not imperatively necessary.
In fact, a (plastic) deformation of the crimp zone 5 may occur in such a
way that the remaining region of the housing 15 is also (partially)
deformed. FIG. 12 is based on the exhaust-gas treatment unit 1 in the
embodiment of FIG. 3. It can be seen that the crimp zone 5 is deformed in
the installed state. A force-locking connection is thereby ensured. The
section of the exhaust-gas-conducting line 7 shown in FIG. 12 may, for
example, be a portion of a cylinder head of an internal combustion engine
11. In this case, the non-illustrated exhaust-gas recirculation line 9
may be mounted by using a diagrammatically illustrated fastening device
or fastener 8 (dash-dotted lines) in such a way that no retention device
for an exhaust-gas treatment unit 1 according to the invention need be
disposed in between.

[0062] FIG. 13 shows a motor vehicle 10 having an internal combustion
engine 11 corresponding to the illustration in FIG. 11. Contrary to FIG.
11, the exhaust-gas treatment units 1 are disposed, as seen in the flow
direction of the exhaust gas, (directly) downstream of the combustion
chambers 14. The exhaust gas is thus purified directly after the
combustion.

[0063] FIG. 14 shows details of a configuration of the exhaust-gas
treatment unit 1 in the exhaust-gas-conducting line 7. The exhaust-gas
treatment unit 1 of FIG. 5 has been used therein as a basis. In this
case, it can be seen even more clearly that primarily the crimp zone 5
and not the exhaust-gas treatment body 3 has been deformed. In this case,
the opening side 2 is simultaneously the inlet side of the exhaust gas to
be purified coming from the exhaust-gas-conducting line 7. Since the
highest thermal loads, and mechanical loads resulting from the pulsation,
are to be expected at that side, the configuration appears to be
particularly expedient, although that is not imperatively necessary. It
can also be seen in this configuration that the exhaust line 12 or an
exhaust manifold can be fastened to the cylinder head of the internal
combustion engine 11 without further intermediate pieces by using the
diagrammatically illustrated fastening device or fastener 8 (dash-dotted
lines). In this way, inter alia, the number of fitting surfaces and
sealing surfaces is reduced.

[0064] The invention thus at least partially solves the technical problems
highlighted in conjunction with the prior art. In particular, a device
has been proposed which can be positioned fixedly in an
exhaust-gas-conducting line without external retention devices. This,
inter alia, simplifies assembly and increases the flexibility of the
configuration of the exhaust-gas treatment unit.